rs3918242 is one of two SNPs in the MMP9 gene associated with increased risk for myocardial infarction, but not coronary artery disease. The relatively weak odds ratios for carriers of one rs3918242(T) allele was 1.14 (p=0.06), and for (T;T) homozygotes, 1.33 (p=0.19). However, this study of 5,000+ Caucasian patients with heart disease also indicated that a composite genotype (i.e. unphased haplotype) of the two MMP9 SNPs (rs3918242 and rs17576, respectively) yielded a significant odds ratio of 1.25 (CI: 1.07 - 1.48, p=0.007) for the (C;T)/(A;G) combination compared to (C;C)/(G;G) combination genotypes.[PMID 17893005]

[PMID 18006768] This MMP9 SNP, located at -1,562 in the promoter region, was associated with further progression of breast cancer; in comparison to the (C;C) genotype, the odds ratio for the rs3918242(C;T) genotype was 3.6 for mixed ethnicities (CI: 1.2-11.1, p=0.001), and for Caucasians only, 9.1 (CI: 1.7-48.4, p=0.01).